Bluetooth Headset Garage Door Opener Update

March 21, 2013 by Mike Szczys 22 Comments

bluetooth-headset-garagedoor-opener-update

[Lou Prado] sent in a link to his new video on using a Bluetooth headset as a garage door opener for your Android device. This isn’t a new hack, and we’ve actually seen him pull it off once before back in 2011. But we’re running this as an update for a couple of reasons. First off, we had forgotten about the hack and it’s worth revisiting. Secondly, the headset which he used with the initial hack has gone out of production. He chose a new model, and the assembly video (embedded after the break) which he made is a treasure trove of best practices to use when hacking consumer electronics.

Here’s how the hardware part of the hack goes. He removes the speaker from the headset and solders the base of a transistor in-line with a resistor to the red wire. The emitter connects to the grounded frame of the USB charging cable which is plugged into an outlet next to your garage door opener. The collector of the transistor is then connected to the garage door opener, along with a common ground connection, allowing audio from the headset to trigger the transistor to open the door.

The systems is secure based on Bluetooth pairing, which was done with his phone before starting the hardware hack.

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Remote Control Command Center Includes RF And IR Functions

March 21, 2013 by Mike Szczys 9 Comments

all-in-one-remote-relay-includes-RF

We’re still not quite sure what to call these projects, but as we’ve said before, it’s a pleasure to see what people are doing to use one remote control to rule them all. The project being developed by [Kalle Löfgren] seeks to simplify the remote controlled items in his home by combining all control into one smart phone app. The linchpin of the system is this command center which lets a smart phone send IR and RF commands to various devices (translated).

We’ve seen this done with pretty beefy microcontrollers, like this project that uses a PIC32. But the communications going on between the smartphone and the base station are very simple, as are the remote control commands which are being relayed. So we’re not surprised to find that this setup just uses an ATmega88, IR LED, Bluetooth Module, and RF module. There is no connection to a computer (the USB simply provides power via a cellphone charger). If you’re interested in how [Kalle] sniffed the protocol for each remote he wrote two other articles which you can find in the write-up linked above.

Heat Your House With Propane (but Not In The Way You’re Thinking)

March 18, 2013 by Mike Szczys 87 Comments

geothermal-heat-pump-charged-with-propane

[Ralph Doncaster] has a geothermal heat pump which is responsible for providing heat for his home. He’s been looking into some hacks that would make it more efficient and decided that the freon (R-22) needed to be tweaked. Some would say the stuff is bad for the environment, so he decided to go a different route. He replaced the Freon with propane, using this rig to make the fuel-grade propane more like cooling-grade propane called r-290.

He purchased the gauge set which is used whenever a technician services an A/C system (but you can also see it in this other A/C propane hack). That’s important because it’s responsible for making sure the old coolant is recaptured (his hose failure nixed this part of the plan) and the new coolant goes where it should at the correct pressure. But before dumping in propane from the local hardware store he needs to dry it out. Fuel-grade propane can have moisture in it, which can be bad for the cooling system. He bought a drier device, the grey bulb seen above, and soldered it on one end to a propane torch fitting and to a valve connection on the other. Now he could remove moisture as he pressurized the system.

Everything is working again, and the cooling side of the system gets much colder. He plans to do more testing as time goes by.

Adding Fireplace Control To Your Home Automation

March 15, 2013 by Mike Szczys 6 Comments

fireplace-automation

[James] has an admirable home automation system which he’s been working on for years. It does things like monitor the state of the garage door, control the lights, and it even notifies him of a power failure. One thing that wasn’t on the system yet are the fireplaces he has in his home. The hardware you see above is how he patched into the fireplace remote control system in order to automate them.

The remote control uses RF to communicate with a base station. Unlike controlling home theater components which use IR, this makes it a bit more difficult to patch into. Sure, we’d love to see some reverse engineering of the protocol so that a simple radio module could be used, but [James] chose the route which would mean the least amount of hacking on his part. He soldered wires onto the PCB for the buttons and connected to them using reed relays. These let the Arduino simulate button presses.

With the rig connected to the home network he has a lot of options. The system can sense if the house is occupied. If it determines that no one is home it will switch off the fireplaces. [James] also mentions the ability to monitor for carbon monoxide or house fires, switching off the gas fireplaces in either case.

Cardboard Lampshade Makes Ordinary Recycling A Centerpiece Of Your Room

March 13, 2013 by Mike Szczys 5 Comments

This cube lamp was assembled using common cardboard. Not only does it look interesting, but it’s basically free with every Ikea purchase since all you need is a source of cardboard, cutting implements, and glue.

[Lindarose92] fabricated the shade out of narrow strips of corrugated cardboard. This particular lamp also has a cardboard base but we’re sure you could use it for just about any light source with doesn’t generate enough heat to cause problems. The build starts out with the tedious process of cutting 5mm by 8cm strips, and you’re going to need a lot of them. Each strip is cut perpendicular to the corrugation, which allows the light to shine through the wave pattern. The strips are then glued into 8cm x 8cm squares, which are in turn glued together into the four by four panels that make up each side of the cube.

Boom, you’re done. And if you get tired of it, just toss the thing in your recycling bin.

[via Hacked Gadgets]

Coffee Pot Aquarium Keeps Fish Warm Without Cooking Them (hopefully)

March 11, 2013 by Mike Szczys 36 Comments

coffee-pot-aquarium

Beta fish are one of the easiest pets to care for. So when [Derek] gave his girlfriend one for Valentine’s day he thought the job was done. Turns out these tropical pets want 75-80 F water and that’s not going to happen in a plain old bowl when you keep your home thermostat in the mid sixties during the winter. While looking for a simple heating solution he stumbled across the idea of using a cheap drip coffee maker as an aquarium.

The two main components are already in place: a clear glass vessel for the water and a way to heat it. The real trick is to use the heating element to gently warm the water to the appropriate temperature. Perhaps the key piece of the project is that the device already had a timer that shut off the heating element. This translates to easy control with his MSP430 microcontroller as it means there’s a relay present. He also patched into the two seven-segment displays to give him feedback on the temperature currently being read by the RL1003 thermistor which is submerged in the water. You’ll also note that he added a few LEDs to the lid to give the aquarium some inner glow.

Wireless Doorbell Battery Monitor

March 7, 2013 by Mike Szczys 10 Comments

wireless-doorbell-battery-monitor

We know exactly what [Dan] is going through. We also bought a cheap wireless doorbell and are plagued by the batteries running down. When that happens, the only way you know is when people start pounding on the door because you’re not answering the bell. Well no more for [Dan]. He built a backup system which monitors the voltage of the batteries on the chime unit.

You can see the small bit of protoboard he used to house the microcontroller and the UI. It’s an ATtiny13 along with a green LED and a single push button. The idea is to use the chip’s ADC to monitor the voltage level of the pair of batteries which power the chime. When it drops below 3V the green LED will come on.

First off, we wish these things would come with better power supply circuits. For instance, we just replaced the CR2032 in an Apple TV remote and measured the voltage at 2.7V. That remote and the chime both run from a 3V source. Can’t they be made to work down to 1.8V? But we digress.

In addition to monitoring voltage [Dan’s] rig also counts the number of times the chime has rung. Every eight seconds it flashes the count in binary, unless he presses the red button to clear the count. This is shown in the video after the break. We guess he wants to know how many times this thing can be used before running the batteries down.

Seriously though, for a rarely used item like this how hard would it be to use ambient light harvesting to help save the batteries? Looking at some indoor solar harvesting numbers shows it might be impossible to only power this from PV, but what if there was a super-cap which would be topped off with a trickle from the panels but would still use the batteries when that runs down?

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